From nobody Mon Mar 21 19:08:34 2022 X-Original-To: bugs@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 7E0E21A20241 for ; Mon, 21 Mar 2022 19:08:35 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4KMkfq2RCPz3spP for ; Mon, 21 Mar 2022 19:08:35 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org (kenobi.freebsd.org [IPv6:2610:1c1:1:606c::50:1d]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 3031D2046A for ; Mon, 21 Mar 2022 19:08:35 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org ([127.0.1.5]) by kenobi.freebsd.org (8.15.2/8.15.2) with ESMTP id 22LJ8ZRp092734 for ; Mon, 21 Mar 2022 19:08:35 GMT (envelope-from bugzilla-noreply@freebsd.org) Received: (from www@localhost) by kenobi.freebsd.org (8.15.2/8.15.2/Submit) id 22LJ8ZuI092733 for bugs@FreeBSD.org; Mon, 21 Mar 2022 19:08:35 GMT (envelope-from bugzilla-noreply@freebsd.org) X-Authentication-Warning: kenobi.freebsd.org: www set sender to bugzilla-noreply@freebsd.org using -f From: bugzilla-noreply@freebsd.org To: bugs@FreeBSD.org Subject: [Bug 262587] panic: lock (sleep mutex) umtxql not locked @ /usr/src/sys/sys/umtxvar.h:262 on 14-current master-n253798-8cdecdecb43 Date: Mon, 21 Mar 2022 19:08:34 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Base System X-Bugzilla-Component: kern X-Bugzilla-Version: CURRENT X-Bugzilla-Keywords: X-Bugzilla-Severity: Affects Only Me X-Bugzilla-Who: mav@FreeBSD.org X-Bugzilla-Status: Open X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: bugs@FreeBSD.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugs.freebsd.org/bugzilla/ Auto-Submitted: auto-generated List-Id: Bug reports List-Archive: https://lists.freebsd.org/archives/freebsd-bugs List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-bugs@freebsd.org MIME-Version: 1.0 ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1647889715; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=dogFQYTKaL8eQPsvUUHO1LQkcAbSP41snHg91+r2WmU=; b=u14+RVjuW73c6Ycy7A+4coq2NC4aK92T7/Tkk+O8NA8bdNu5E4FJ/43sOttACgmSoZFK43 9g3czy3p9gv3TKdGfy7QVXKaxpqP1pm9KcyHXWvhY0Q8f9Li5pGiGF5b4bosShoCUN/lA4 pgXCWMUstaS1zQ7tLqO7CWedq78KlY7IJJD0eXDA0uEf5Z4aMcjFE3+HwbB+smjNI1iW+i 0V1EKQxLRV/LmaQTpvrMNwt+J6P7Zb2B3NVfjTtB7/gp8duBLXeZOKJvtWchhKGhw0M0Kr 0mGlOf5Go3OXCrz9aFE4ISBODGMKJaZQfHU2Sen6Iw9iHYNYiNRnJELNeol64w== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1647889715; a=rsa-sha256; cv=none; b=ccCRSRMPn6bFwd04f6xacMLI7TwlazZgIgWAT2uo478fjTL81DZRt0/GC06ztwiB3q2wrE LoRgK7HAb869iv+I34vWXTK2H1Ym3jF2BUG9pPhitA+E/7tkaRrie25vxsBzkE4Lfo6yt0 jvE//+XrBnl31HxwhLZOd5IYaGiDOT/kpX0fxCSE3nsyy4wweUFfCqzA6O3aWAxUxWNdjB d9SlkUqhgmvVTHO9R19622mLySwTWdTD8woLTCNC7WiqpzKRk4N4UxI6Kq2WGtOtd3nVLO XEis00nctLKC7Q78ekwWrNsPL9EeM6YZRQyLet7XygGdIlhKY5GcnIjSTFJS5A== ARC-Authentication-Results: i=1; mx1.freebsd.org; none X-ThisMailContainsUnwantedMimeParts: N https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D262587 --- Comment #18 from Alexander Motin --- OK. I still don't understand how can it be safe to change the lock when th= ere seems to be a window between umtxq_getchain() and mtx_lock() inside the umtxq_lock(), but what would you say about this patch: --- a/sys/kern/kern_umtx.c +++ b/sys/kern/kern_umtx.c @@ -808,8 +808,10 @@ umtxq_sleep(struct umtx_q *uq, const char *wmesg, if (error !=3D 0) break; } - error =3D msleep_sbt(uq, &uc->uc_lock, PCATCH, wmesg, + error =3D msleep_sbt(uq, &uc->uc_lock, PCATCH | PDROP, wmes= g, sbt, 0, flags); + uc =3D umtxq_getchain(&uq->uq_key); + mtx_lock(&uc->uc_lock); if (error =3D=3D EINTR || error =3D=3D ERESTART) break; if (error =3D=3D EWOULDBLOCK && (flags & C_ABSOLUTE) !=3D 0= ) { It seems even before my change code could try on the old lock due to uc nev= er being updated, so I did it this way instead of using umtxq_lock(). --=20 You are receiving this mail because: You are the assignee for the bug.=